Sintering apparatus.



R. PALMER.

SINTBEING APPARATUS.

APPLIQMIQE FILED EEB. 1o, 1909.

Wnesses: m/enor Rober@ Palmer,

M@ T bywfw UNITED sTATE-s PATENT oEEioE.

ROBERT .-PALMER, or LAncHMoNT, NEW YORK, AssIGNoR To GENERAL ELEc'rmc'COMPANY, A CORPORATION OF NEW YORK.' r

smrEmNG APEARAT'US.

Specification of Letters Patent. i

ifatemeilDec. 7, 1909.,

applicants inea February 1o, i909. serial No. 477,181.

Larchmonh county of lVestchester, State of New York, have inventedcertain new and useful Improvements in Sintering Apparatus, of Which thefollowing is a specification.

The highly refractory metals, such .as tungsten, molybdenum, tantalum,andthe like, are compacted into a homogeneous body of metal With thegreatest diiiiculty. One method of procedure consists in irst obtain inga loosely coherent body of metal, either by, pressing the iine metalpowder into a mold, or by uniting the metal particles into a coherentbody by means of a binder, which can be later removed. This body ofmetal is then further treated by subjecting it to a high temperature, asby the passage of an electric current, which causes the particles toWeld or sinter together, the body meanwhile shrinking in volume andbecoming compact and dense.

My invention relates to an apparatusfor sintering bodies of this kind,and more especially comparatively thick Wiresand rods of. highlyrefractorymetal, which require the expenditure of several kilowatts ofenergy. The clamps, which serve to hold the Wires or rods and conductcurrent to the same, 'are artificially cooled Which prevent fusion of'thesame at the points of Contact With the bodies to be sintered. Therods are supported in such a4 manner that it *is possible for themreadily to draw together, or shrink, when sintering. The Weight of themovable clamp Ais counter-balanced by means of a float displacing a bodyof heavy liquid, preferably a conductive liquid, such as mercury.

This expedient avoids the possibility of the sintering rod being pulledapart when in a plasti/c state. The operation is carried on in a vacuum,or a suitable gas, Within a metallic envelop, Which vcan rapidly absorband dissipate the great amount of heat which is generated. The envelopis. provided with a suitable Window, so as to enable the operator.

to observe and regu ate the temperature to I which the body is raised.

The novel 'features of my invention are pointed out morespeeiiically inthe appended claims. y

In the accloml'nanying drawings, Figure 1 is au elevationa l viewpartlyin section of the sintering apparatus; 2 Ais asectional view ofthe treating envelop taken at ri t angles tothe plane `of F i-g.- 1-;andFig. -31 s a' cross-section through the' line 3;-3 of the uppersupporting clamp shown in Fig'. 2. f

- Referring to Fig. 1, the .framework 1, preferably made of-Wood',supports two parallel-guide rods 2.. The treat-ingv envelop 3,

made of copper, iron, or some other suit- 'able metal. is slidablymovable along the guide rods l2, the latter passing' through theperforated guiding lugs 4 of the sinte'ring envelop.. A base 5, uponWhich-the envelop 3 rests When ill-position, is made of somefireproofand insulating material, as asbestos-board Vor slate. The -sinteringenvelop is provided with' a suitable window G, best -shown in Fig. 2. Inorder to remove the Window from the intense heat it is placed in atubular extending `portion in which a strip of 'mica 7 is firmly seated.The treating envelop is also provided withl a handle 8@ It is supportedby means of a rope or tiexible Wire 9 running over suitable pulleysandhaving attached to itsfree ends a counter-weight 10. The --envelop vissupplied with gas through a tube 11,'as clearly shown.

The Wire or rod to be sintered is held at one end bya fixed clamp' 12,.which is mounted on 'the tubularsupports 13, 14, and held at its otherend by amovable clamp 15 mounted on the tubular supports 16, 17.. A flowi of cooling' fluid-is maintained through the clamps. As Will be moreclearlyexplained inconnection With'Fig. '2, the path of flow is throughtube 14, clamp'lQ, tube 1,3', conf necting tube 18, tube 1 6, clam 15',tube 17 and outlet tube 19.. The mo'va leclamp 15, with its attachedtubes, is Supported by rod 20, having attached to its lower end a floatThis'float can be .conveniently made of aluminum, or in'factany otherlight body, and is immersed in this case in a body of mercury Vcontainedin an upright tube 2Q.

Current is supplier1 to the clamp 12 by a' conductor 23, which isattached to the buse of the tube 13, and current is supplied tothemovable clamp by means of conductor 24.

Which is attached to the 1nercury-containing tube 2Q, the currentbeinggconductcd b v the mercury to the4 supporting rod 20,' and .iu turnthereby to the clamp 15.

The structure of the clamps 12 und 15 may be better understood byreference to with reference to the Hows at right angles across vlistedmember 25 and a movable member 26 pressed against the fixed member bymeans of a spring 27. The structure ot the clamp path taken by the Watermaybe best understood by reference to Fig. 3. lt Will'be here seen thatthe Water entering vby tubev 3 takes a V shaped course through theclamp, against the' side pressed againstthe heated Wire, and leavesClamp 15 similarly consists of a fixed porflowing directly the clamp bythe tubel-l. g

`and means tor passing tion '29 and movable portion 30 springpressedagainst the Xed portion. The waterenters the lower portion of. theclamp,

the upper portion and then descends, leavinggthe clamp on thev oppositesi-de, as shown by the dotted lines.

llnpractice the rod. or wire to be sintered is inserted between theclamps, and the treating envelop 3 isv drawn down over the sameso as torest squarely upon the plate 5. .A flouv of gas, such as hydrogen, isthen started through the tube 11' until the -air Within' is displaced.rlhe rod to be sintered is gradually raised to white heat by a current-fromthe secondary of a transformer capable of furnishing 100er moreamperes. rlhe shrinkage of the rod causes 1t to drav:

up the movable clamp,

without danger of rupturing the sintering wire. The progress ,of .thesmtermg may thereby continually maintaining electricalr Contact at bothends be observed by .the operator through the window 6, and he canregulate the current accordingly.

.tion of' a fixed clamp, a movable Vt] hat l claim as 'new and desire tosecure by Letters Patent ot' the United States, isf-- 1. lin a thermoerect'ric apparatus, the combination of an envelop, means for supplyinga gas to said envelop, and a plurality or Water-cooled yclamps torholding material to be treated, at least one of said clamps being freelymovable.

2; ln a sintering apparatus, the combination of a container, means forsupplying gas thereto, means for clamping a body to be sintered and forconducting current thereto, a cooling luid through said clamping andcurrentconducting means. 4

3. In a sintering apparatus, the combinaclamp, meansV for7counterbalancing 'the Weight of said movable clamp, and means forconducting current to said clamps.

In a sintering apparatus, the combination of -a fixed clamp, a movableclamp, a lioat attached to said movable clamp and supported by a liquid,and means plying current to said clamps.

5. In a sintering apparatus, the combination .of coperating water cooledclamps, one of which is freely movable, electrical conductorsvoperatively connected to said clamps, and a lioat immersed in a body of:mercury and rigidly attached to the movable clamp for supporting thesame.

ln Witness whereof, l have hereunto set my hand this 8th day ofFebruary, 1909.

, ROBERT PALMER. YVitnesses:

BENJAMIN B. HULL, HELM" RFORD.

for supfl (l

